Iridium, Iridium, Iridium

Walter Nissen (dk058@cleveland.Freenet.Edu)
Fri, 11 Sep 1998 09:53:42 -0400 (EDT)

A couple of weeks ago I wrote: 
 
> So then Ir 03 and Ir 76, in some order, are Ir P18, the 
> operational craft, and Ir P1B, the standby. 
 
> Who will be the first to ascertain which is which? 
 
Developments have been slightly more complicated than this.  Ir P15  69 
has been removed from the regular polygon formed by the 11 operating 
satellites in P1 (some other sources call this plane 2).  One of the new 
objects has taken her place.  The other has apparently become Ir P18  76. 
 
Here is a QuickSat excerpt augmented with notes based on new developments: 
 
***  1998 Sept 10  *** Times are UT *** 
       H  M  S  AL AZI C  -previous- com new-n 
24905 10 10  5  68 267 C  Ir P10  24 
25319 10 15 36  60 268 C  Ir P15  69 wak P1B or P1U 
25106 10 19 16  55 269 C  Ir P11  47 
25107 10 28 24  45 270 C  Ir P12  48 
25108 10 37 31  37 272 C  Ir P13  49 
24903 10 46 38  31 273 C  Ir P14  26 
25431 10 55 50  25 275 C  Ir      03 new P15R 
24907 11  4 49  21 277 C  Ir P16  22 
24906 11 13 53  17 278 C  Ir P17  23 
25320 11 22 21  14 280 C  Ir P1T  71 wak 
25432 11 22 46  14 280 C  Ir      76 new P18 
24904 11 32  0  11 281 C  Ir P19  25 
25104 11 41  1   9 283 C  Ir P1A  45 
25105 11 44  1   8 283 C  Ir P1S  46 wak 
24905 11 50  0   7 285 C  Ir P10  24 
 
Notes: 
 
-previous- contains the name I suggested in my previous post describing a 
           more useful nomenclature for the Iridial constellation. 
 
com        contains a comment 
     new   means the -previous- column contains only the number from OIG 
           for an object newly launched. 
     wak   means the orbital period is out of whack, or wacko, because the 
           object is not part of the 11-object regular polygon formed by 
           the operating satellites. 
 
new-n      contains a new name for the object, based on its new status in 
           the constellation 
 
 
New status 
 
operating satellites in P1 
Ir P10  24/46 
Ir P11  47 
Ir P12  48 
Ir P13  49 
Ir P14  26 
Ir P15R 03 
Ir P16  22 
Ir P17  23 
Ir P18  76 
Ir P19  25 
Ir P1A  45 
 
other objects in the same plane 
Ir P1B  69     or P1U, formerly P15 
Ir P1S  46/24 
Ir P1T  71 
 
 
It is not clear whether Ir P15  69 has become Ir P1B  69 or Ir P1U  69. 
P1B would designate an object on standby, awaiting a role as a future 
replacement.  P1U would designate a failed object.  I suppose we are stuck 
with P1B until some clarification is available, though I eagerly solicit 
any facts or opinions about this. 
 
 
I find the following table very useful as a quick reference when I am 
forced to deal with the irregular numbers so often labelled "common name": 
 
P00  64   P10  24*  P20  32   P30   5   P40   9*  P50  39 
P01  65   P11  47   P21  33   P31   6   P41  10* 
P02  66   P12  48   P22  57   P32   7   P42  52   P52  17 
P03  67   P13  49   P23  58   P33   8   P43  12   P53  15 
P04  68   P14  26   P24  59   P34   4   P44  13 
P05  74   P15R 03   P25  60   P35  35   P45  14   P55  38 
P06  72   P16  22   P26  55   P36  61   P46  16   P56  41 
P07  73   P17  23   P27  28   P37  19   P47  53   P57  43 
P08  70   P18  76   P28  29   P38  34   P48  56   P58  18* 
P09  62   P19  25   P29  30   P39  37   P49  50   P59  42 
P0A  63   P1A  45   P2A  31   P3A  36   P4A  54   P5A  40 
 
P0B  75   P1?  69             P3B  51 
          P1S  46*  P2S  27             P4S  11   P5S  20* 
          P1T  71                                 P5T  44 
                                                  P5U  21 
 
                                                       77 
                                                       79 
                                                       80 
                                                       81 
                                                       82 
 
*   numbers have been confused, resolution uncertain 
 
 
Accepting the numbers from OIG posted by Jeff Hunt, 79 satellites have 
been launched, numbered 3 thru 77 and 79 thru 82.  1, 2, and 78 are 
unused, unless 1 and 2 are used for the 2 Sim objects. 
 
 
I heard a radio news report that Iridium has postponed start-up of their 
new service from September 23rd to November 1st. 
 
 
Cheers. 
 
Walter Nissen                   dk058@cleveland.freenet.edu
-81.8637, 41.3735, 256m elevation

---

I'm all for progress.  It's change I can't stand.   Mark Twain